Plant Virology Laboratory, Plant Protection Institute, Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, Beltsville, Maryland 20705.
Proc Natl Acad Sci U S A. 1981 Aug;78(8):5014-5. doi: 10.1073/pnas.78.8.5014.
A complex of considerable stability is possible between the 5' end of U1 RNA and a specific nucleotide sequence of the potato spindle tuber viroid complement. Because base-pairing between the 5' end of U1 RNA and the ends of introns is believed by some to be responsible for the precise alignment and correct excision of introns, the U1-related sequence may represent the two ends of a presumed intron ancestor of the viroid complement after circularization.
U1 RNA 的 5' 端与马铃薯纺锤块茎类病毒互补序列的特定核苷酸序列之间可能存在相当稳定的复合物。由于某些人认为 U1 RNA 的 5' 端与内含子末端之间的碱基配对负责内含子的精确排列和正确切除,因此 U1 相关序列可能代表类病毒互补物经过环化后的假定内含子祖先的两个末端。